Pulleys interchangeable?

[Swing]

Ok thanks. Could be because of simply different width of the pulley and length of the bolts,.

Originally Posted by WeeYari

If only that were true.

It is not really a matter of consuming less power. The light weight achieves that. Going 10% underdrive was a way of making the pulley lighter still, while still providing enough rotation to drive a/c, alt, and water pump.

But if it's 10% smaller then it's like a 10% smaller gear. It means that for every revolution of the engine, the waterpump will drive 10% less, costing 10% less energy. The alternator is a different story, I guess the same for a/c if you have it. The alternator will have a certain load to generate a certain amount of current, so that will always be the same amount of resistance.

So why wouldn't underdriving work? Of course I could also put a bigger pulley on the waterpump (might be easier to find) to have the same effect.

Of course, the lightweight idea is straightforward and clear.